Chromosome translocations have been associated with many types of human leukemia and lymphoma. It is accepted that these translocations disrupt proto-oncogenes that are involved in the pathogenesis of these malignancies [Bishop, J. M., Cell, 64: 235 (1991); and Klein and Klein, Nature, 315: 190 (1985)]. The analysis of chromosome translocations in leukemia and lymphoma has led to the improved understanding of known oncogenes, such as c-myc and c-abl, and the discovery of new oncogenes, such as bcl-2 [Bakhshi et al., Cell, 41: 899 (1985); Cleary et al., Cell, 47: 19 (1986); Leder et al., Science, 222: 765 (1983); Showe and Croce, Annu. Rev. Immunol., 5: 253 (1987); Swenson et al., Cell, 47: 861 (1986)].
The t(11;14)(q13;q32) translocation is an important abnormality associated with B-lymphocytic malignancy [Fukuhara et al., Cancer Res., 39: 3119 (1979); Nishida et al., Cancer Res., 49: 1275 (1989); Van den Berghe et al., Cancer, 44: 188 (1979); and Weisenburger et al., Blood, 69: 1617 (1987)]. That abnormality has been reported in chronic lymphocytic leukemia (CLL), multiple myeloma, and lymphoma [Yunis, J., Science, 221: 227 (1983); Van den Berghe et al., supra; Fukuhara et al., supra; Abe et al., Cancer, 61: 483 (1988); Chaganti et al., Cytogenet. Cell Genet., 45: 93 (1987); and Barlogie et al., Acta Hematol., 78: 171 (Suppl.; 1987)]. Breakpoints in chromosomal region 14q32 occur in the joining region of the immunoglobulin heavy chain (IgH) gene [Meeker et al., Blood, 74: 1801 (1989); Tsujimoto et al., Nature (London), 315: 340 (1986); and Tsujimoto et al., Science, 224: 1403 (1984)]. Chromosome 11 breakpoints occur in a region called the bcl-1 (B-cell lymphoma/leukemia 1) locus, that was known to cover at least 63 kb of chromosome 11 [Koduru et al., Oncogene, 4: 929 (1989); Meeker et al. (1989), supra; Rabbitts et al., Oncogene, 3: 99 (1988); and Tsujimoto et al. (1986), supra]. A high proportion of the documented chromosome 11 breakpoints are found in a subregion of the locus called the major translocation cluster (MTC) [Meeker et al. (1989); Tsujimoto et al. (1986)].
By analogy to other translocations, a new gene, a putative dominant oncogene that was activated by the t(11;14) (q13;q32) translocation, has been postulated for the bcl-1 locus for many years. However, the identification of such a bcl-1 gene has been elusive, and it had not been well characterized.
In one approach to identify the bcl-1 gene, a number of candidate oncogenes from 11q13 were mapped by using the radiation hybrid technique [Richard et al., Am. J. Hum. Genet., 49: 1189 (1991); and Meeker et al., Blood, 76: 239a (abst. suppl.; 1990)]. That study indicated whether any known genes mapped close to the bcl-1 locus. Potential bcl-1 candidate genes CD5, CD20, c-sea, and protein phosphatase la were eliminated by that analysis.
In parathyroid adenomas, a gene called PRAD1 was shown to be occasionally activated by a pericentric inversion of chromosome 11 [Motokura et al., Nature (London), 350: 512 (1991); and Rosenberg et al., Oncogene, 6: 449 (1991)]. Motokura et al. show in FIG. 2(a) the nucleotide sequence and predicted amino acid sequence of PRAD1 cDNA. The PRAD1 gene is considered therein to be a bcl-1-linked candidate oncogene.
Xiong et al., Cell, 65: 691 (1991), found the bcl-1 gene (called the cyclin D1 gene) in a screen for human genes that complement yeast cells deficient in G.sub.1 cyclin activity.
Matsushime et al., Cell, 65: 701 (1991), found an apparent murine homolog of bcl-1 (called Cyl-1) by screening a mouse macrophage cell line for genes that might regulate G.sub.1 progression in the presence of colony-stimulating factor 1.
Abnormalities of the bcl-1 locus are important in several subtypes of B-lymphocytic leukemia and lymphoma [Medeiros et al, Blood, 76: 2086 (1990); Rimokh et al., Genes Chromosomes Cancer, 2: 223 (1990); and Williams et al., Blood, 76: 1387 (1990)]. Further, the bcl-1 locus has been implicated in several other types of cancer. Amplifications of bcl-1 are detected in approximately 20% of breast cancer and squamous cell cancers [Ali et al., Oncogene, 4: 89 (1989); Berenson et al., Oncogene, 4: 1111 (1989); and Theillet et al., Oncogene, 5: 147 (1990)]. Data indicates that bcl-1 is expressed in human tumor cell lines representing those tumor types, and that there is an apparent correlation between amplification and expression in squamous cell and mammary carcinomas [Lammie et al., Oncogene, 6: 493 (1991)].
Bcl-1 is known to be amplified without rearrangement in about a third of head and neck squamous cell carcinomas and a small number of squamous cell lung carcinomas, and is coamplified with hst and int-2 in a subset of human breast carcinomas [Berenson et al., Oncogene, 4: 1111 (1989); Berenson et al., Oncogene, 5: 1343 (1990); Ali et al., Oncogene, 4: 89 (1989); and Theillet et al., Oncogene, 5: 147 (1990)]. Further, bcl-1 is also amplified in bladder carcinomas [Proctor et al., Oncogene, 6: 789 (1991)]. Exploration of the pathophysiology of those diseases has awaited the identification and characterization of the bcl-1 gene.
Identified herein is a gene that is a member of the cyclin gene family whose expression is shown to be deregulated in two leukemia samples with the t(11;14) (q13;q32) translocation. That gene is considered to be the bcl-1 gene.
This invention characterizes the bcl-1 gene and provides nucleic acid probes to identify translocations and amplifications involving the bcl-1 locus that are associated with cancers. The structure of the bcl-1 gene and its relationship to translocations that occur within the bcl-1 locus are delineated by the instant invention. Further, the instant invention provides the first evidence that when t(11;14) (q13;q32) occurs that the bcl-1 gene is overexpressed as indicated by elevated levels of bcl-1 mRNA.
The nucleic acid probes of the instant invention are important for molecular diagnosis and/or prognosis of cancer and in cell cycle progression studies. Particularly, the bcl-1 probes provide an improved approach to diagnosing/prognosing certain malignant lymphomas, a prolymphocytic variant of CLL, a proportion of multiple myelomas, and 20% of solid cancers, such as, breast and squamous cell cancers.
Prior to the instant invention, ten percent of human lymphomas were diagnosed by use of a light microscope only. Now, this invention provides the molecular tools to confirm such a diagnosis and allow for more exact clinical care. The probes of this invention could be used to analyse molecularly all human cancer specimens.